[root@jeven ~]# touch --help
Usage: touch [OPTION]... FILE...
Update the access and modification times of each FILE to the current time.
A FILE argument that does not exist is created empty, unless -c or -h
is supplied.
A FILE argument string of - is handled specially and causes touch to
change the times of the file associated with standard output.
Mandatory arguments to long options are mandatory for short options too.
  -a                     change only the access time
  -c, --no-create        do not create any files
  -d, --date=STRING      parse STRING and use it instead of current time
  -f                     (ignored)
  -h, --no-dereference   affect each symbolic link instead of any referenced
                         file (useful only on systems that can change the
                         timestamps of a symlink)
  -m                     change only the modification time
  -r, --reference=FILE   use this file's times instead of current time
  -t STAMP               use [[CC]YY]MMDDhhmm[.ss] instead of current time
      --time=WORD        change the specified time:
                           WORD is access, atime, or use: equivalent to -a
                           WORD is modify or mtime: equivalent to -m
      --help     display this help and exit
      --version  output version information and exit
Note that the -d and -t options accept different time-date formats.
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'touch invocation'

-a：仅修改文件的访问时间（atime）。
-c：如果文件不存在，不要创建新文件。
-d：设置文件的时间戳为指定时间，可以使用各种格式的日期时间值，如“2021-12-31 23:59:59”、“next Friday”、“+3 hours”等。
-m：仅修改文件的修改时间（mtime）。
-r：将目标文件的时间戳与指定文件的时间戳相同。
-t：设置文件的访问时间和修改时间为指定时间，格式与-d选项相同。
--help：在线帮助；
--version：显示版本信息。

[root@jeven ~]# touch --version
touch (GNU coreutils) 8.22
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by Paul Rubin, Arnold Robbins, Jim Kingdon,
David MacKenzie, and Randy Smith.

[root@jeven tmp]# touch file01.txt
[root@jeven tmp]# ls
file01.txt

[root@jeven tmp]# file file01.txt 
file01.txt: empty

[root@jeven tmp]# echo aa > file01.txt 
[root@jeven tmp]# file file01.txt 
file01.txt: ASCII text

[root@jeven tmp]# stat file01.txt 
  File: ‘file01.txt’
  Size: 3           Blocks: 8          IO Block: 4096   regular file
Device: fd00h/64768d  Inode: 18451793    Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2023-07-10 19:55:25.464098671 +0800
Modify: 2023-07-10 19:55:21.487098520 +0800
Change: 2023-07-10 19:55:21.487098520 +0800
 Birth: -

touch -t $(date +"%Y%m%d%H%M.%S") file01.txt

[root@jeven tmp]# touch -c aa
[root@jeven tmp]# ls
file01.txt